COLLISION PREVENTION IN HOISTWAY WITH TWO ELEVATOR CARS

摘要

An elevator system (8) includes a hoistway (9) having a plurality of cars (10, 11) traveling therein, the hoistway includes a steel tape (14), each car having two tape readers (20, 21; 22, 23) which feed corresponding position detectors (29, 30: 31, 32) to provide independent position signals (35, 26: 37, 38). A group controller (52) assigns calls in a fashion to avoid collisions. Controllers (45, 46) for each car communicate with each other and when deemed necessary, either lower the speed, acceleration, deceleration of one or both of the cars, or stop (with or without reversing) one or both of the cars. Independent processors (41, 42) will drop the brake (49, 50) of either or both cars if they come within a first distance of each other, or will engage the safeties (18, 19) of either or both cars if they come within a lesser distance of each other.